diff --git a/README.md b/README.md
index 9e225d0..acfd01a 100644
--- a/README.md
+++ b/README.md
@@ -1,18 +1,23 @@
-# xlsx
+# [:green_book: SheetJS js-xlsx](http://sheetjs.com)
 
 Parser and writer for various spreadsheet formats.  Pure-JS cleanroom
 implementation from official specifications, related documents, and test files.
 Emphasis on parsing and writing robustness, cross-format feature compatibility
 with a unified JS representation, and ES3/ES5 browser compatibility back to IE6.
 
-[**In-Browser Demo**](http://oss.sheetjs.com/js-xlsx)
+This is the community version.  We also offer a pro version with performance
+enhancements and additional features by request.
 
-[**Source Code**](http://git.io/xlsx)
+[**Pro Version**](http://sheetjs.com/pro)
 
-[**Commercial Support**](http://sheetjs.com/reinforcements)
+[**Commercial Support**](http://sheetjs.com/support)
 
 [**Rendered Documentation**](https://sheetjs.gitbooks.io/docs/)
 
+[**In-Browser Demos**](http://sheetjs.com/demos)
+
+[**Source Code**](http://git.io/xlsx)
+
 [**File format support for known spreadsheet data formats:**](#file-formats)
 
 ![circo graph of format support](formats.png)
diff --git a/bits/42_sstxml.js b/bits/42_sstxml.js
index f3e2461..778356b 100644
--- a/bits/42_sstxml.js
+++ b/bits/42_sstxml.js
@@ -27,7 +27,7 @@ var parse_rs = (function parse_rs_factory() {
 	var tregex = matchtag("t"), rpregex = matchtag("rPr"), rregex = /<(?:\w+:)?r>/g, rend = /<\/(?:\w+:)?r>/, nlregex = /\r\n/g;
 	/* 18.4.7 rPr CT_RPrElt */
 	var parse_rpr = function parse_rpr(rpr, intro, outro) {
-		var font = {}, cp = 65001;
+		var font = {}, cp = 65001, align = "";
 		var m = rpr.match(tagregex), i = 0;
 		if(m) for(;i!=m.length; ++i) {
 			var y = parsexmltag(m[i]);
@@ -41,9 +41,11 @@ var parse_rs = (function parse_rs_factory() {
 				/* 18.8.36 shadow CT_BooleanProperty */
 				/* ** not required . */
 				case '<shadow':
+					if(!y.val) break;
 					/* falls through */
 				case '<shadow>':
-				case '<shadow/>': break;
+				case '<shadow/>': font.shadow = 1; break;
+				case '</shadow>': break;
 
 				/* 18.4.1 charset CT_IntProperty TODO */
 				case '<charset':
@@ -53,9 +55,11 @@ var parse_rs = (function parse_rs_factory() {
 
 				/* 18.4.2 outline CT_BooleanProperty TODO */
 				case '<outline':
+					if(!y.val) break;
 					/* falls through */
 				case '<outline>':
-				case '<outline/>': break;
+				case '<outline/>': font.outline = 1; break;
+				case '</outline>': break;
 
 				/* 18.4.5 rFont CT_FontName */
 				case '<rFont': font.name = y.val; break;
@@ -73,7 +77,12 @@ var parse_rs = (function parse_rs_factory() {
 
 				/* 18.4.13 u CT_UnderlineProperty */
 				case '<u':
-					if(y.val == '0') break;
+					if(!y.val) break;
+					switch(y.val) {
+						case 'double': font.uval = "double"; break;
+						case 'singleAccounting': font.uval = "single-accounting"; break;
+						case 'doubleAccounting': font.uval = "double-accounting"; break;
+					}
 					/* falls through */
 				case '<u>':
 				case '<u/>': font.u = 1; break;
@@ -104,7 +113,7 @@ var parse_rs = (function parse_rs_factory() {
 				case '<family': font.family = y.val; break;
 
 				/* 18.4.14 vertAlign CT_VerticalAlignFontProperty TODO */
-				case '<vertAlign': break;
+				case '<vertAlign': align = y.val; break;
 
 				/* 18.8.35 scheme CT_FontScheme TODO */
 				case '<scheme': break;
@@ -114,9 +123,22 @@ var parse_rs = (function parse_rs_factory() {
 			}
 		}
 		var style = [];
-		if(font.b) style.push("font-weight: bold;");
-		if(font.i) style.push("font-style: italic;");
+
+		if(font.u) style.push("text-decoration: underline;");
+		if(font.uval) style.push("text-underline-style:" + font.uval + ";");
+		if(font.sz) style.push("font-size:" + font.sz + ";");
+		if(font.outline) style.push("text-effect: outline;");
+		if(font.shadow) style.push("text-shadow: auto;");
 		intro.push('<span style="' + style.join("") + '">');
+
+		if(font.b) { intro.push("<b>"); outro.push("</b>"); }
+		if(font.i) { intro.push("<i>"); outro.push("</i>"); }
+		if(font.strike) { intro.push("<s>"); outro.push("</s>"); }
+
+		if(align == "superscript") align = "sup";
+		else if(align == "subscript") align = "sub";
+		if(align != "") { intro.push("<" + align + ">"); outro.push("</" + align + ">"); }
+
 		outro.push("</span>");
 		return cp;
 	};
diff --git a/bits/48_stybin.js b/bits/48_stybin.js
index 37ef6fe..987ad9b 100644
--- a/bits/48_stybin.js
+++ b/bits/48_stybin.js
@@ -47,6 +47,7 @@ function parse_sty_bin(data, themes, opts) {
 	for(var y in SSF._table) styles.NumberFmt[y] = SSF._table[y];
 
 	styles.CellXf = [];
+	styles.Fonts = [];
 	var state = [];
 	var pass = false;
 	recordhopper(data, function hopper_sty(val, R_n, RT) {
@@ -54,7 +55,9 @@ function parse_sty_bin(data, themes, opts) {
 			case 0x002C: /* 'BrtFmt' */
 				styles.NumberFmt[val[0]] = val[1]; SSF.load(val[1], val[0]);
 				break;
-			case 0x002B: /* 'BrtFont' */ break;
+			case 0x002B: /* 'BrtFont' */
+				styles.Fonts.push(val);
+				break;
 			case 0x0401: /* 'BrtKnownFonts' */ break;
 			case 0x002D: /* 'BrtFill' */ break;
 			case 0x002E: /* 'BrtBorder' */ break;
diff --git a/bits/90_utils.js b/bits/90_utils.js
index 9df6d87..eb2f869 100644
--- a/bits/90_utils.js
+++ b/bits/90_utils.js
@@ -102,7 +102,7 @@ function make_csv_row(sheet/*:Worksheet*/, r/*:Range*/, R/*:number*/, cols/*:Arr
 }
 
 function sheet_to_csv(sheet/*:Worksheet*/, opts/*:?Sheet2CSVOpts*/)/*:string*/ {
-	var out = "";
+	var out = [];
 	var o = opts == null ? {} : opts;
 	if(sheet == null || sheet["!ref"] == null) return "";
 	var r = safe_decode_range(sheet["!ref"]);
@@ -116,10 +116,10 @@ function sheet_to_csv(sheet/*:Worksheet*/, opts/*:?Sheet2CSVOpts*/)/*:string*/ {
 		row = make_csv_row(sheet, r, R, cols, fs, rs, FS, o);
 		if(row == null) { continue; }
 		if(o.strip) row = row.replace(endregex,"");
-		out += row + RS;
+		out.push(row + RS);
 	}
 	delete o.dense;
-	return out;
+	return out.join("");
 }
 
 function sheet_to_txt(sheet/*:Worksheet*/, opts/*:?Sheet2CSVOpts*/) {
diff --git a/docbits/00_intro.md b/docbits/00_intro.md
index db9cb64..47ee9fa 100644
--- a/docbits/00_intro.md
+++ b/docbits/00_intro.md
@@ -1,18 +1,23 @@
-# xlsx
+# [:green_book: SheetJS js-xlsx](http://sheetjs.com)
 
 Parser and writer for various spreadsheet formats.  Pure-JS cleanroom
 implementation from official specifications, related documents, and test files.
 Emphasis on parsing and writing robustness, cross-format feature compatibility
 with a unified JS representation, and ES3/ES5 browser compatibility back to IE6.
 
-[**In-Browser Demo**](http://oss.sheetjs.com/js-xlsx)
+This is the community version.  We also offer a pro version with performance
+enhancements and additional features by request.
 
-[**Source Code**](http://git.io/xlsx)
+[**Pro Version**](http://sheetjs.com/pro)
 
-[**Commercial Support**](http://sheetjs.com/reinforcements)
+[**Commercial Support**](http://sheetjs.com/support)
 
 [**Rendered Documentation**](https://sheetjs.gitbooks.io/docs/)
 
+[**In-Browser Demos**](http://sheetjs.com/demos)
+
+[**Source Code**](http://git.io/xlsx)
+
 [**File format support for known spreadsheet data formats:**](#file-formats)
 
 ![circo graph of format support](formats.png)
diff --git a/index.html b/index.html
index ef3cef6..97730c2 100644
--- a/index.html
+++ b/index.html
@@ -18,26 +18,34 @@
 #b64data{
 	width:100%;
 }
+a { text-decoration: none }
 </style>
 </head>
 <body>
-<b>JS-XLSX Live Demo</b><br />
-Output Format:
-<select name="format" onchange="setfmt()">
+<pre>
+<b><a href="http://sheetjs.com">SheetJS Data Preview Live Demo</a></b>
+(Base64 text works back to IE6; drag and drop works back to IE10)
+
+<a href="https://github.com/SheetJS/js-xlsx">Source Code Repo</a>
+<a href="https://github.com/SheetJS/js-xlsx/issues">Issues?  Something look weird?  Click here and report an issue</a>
+Output Format: <select name="format" onchange="setfmt()">
 <option value="csv" selected> CSV</option>
 <option value="json"> JSON</option>
 <option value="form"> FORMULAE</option>
+<option value="html"> HTML</option>
 </select><br />
-
 <div id="drop">Drop a spreadsheet file here to see sheet data</div>
-<p><input type="file" name="xlfile" id="xlf" /> ... or click here to select a file</p>
+<input type="file" name="xlfile" id="xlf" /> ... or click here to select a file
+
 <textarea id="b64data">... or paste a base64-encoding here</textarea>
 <input type="button" id="dotext" value="Click here to process the base64 text" onclick="b64it();"/><br />
-Advanced Demo Options: <br />
-Use Web Workers: (when available) <input type="checkbox" name="useworker" checked><br />
-Use Transferrables: (when available) <input type="checkbox" name="xferable" checked><br />
-Use readAsBinaryString: (when available) <input type="checkbox" name="userabs" checked><br />
+<b>Advanced Demo Options:</b>
+Use Web Workers: (when available) <input type="checkbox" name="useworker" checked>
+Use Transferrables: (when available) <input type="checkbox" name="xferable" checked>
+Use readAsBinaryString: (when available) <input type="checkbox" name="userabs" checked>
+</pre>
 <pre id="out"></pre>
+<div id="htmlout"></div>
 <br />
 <!-- uncomment the next line here and in xlsxworker.js for encoding support -->
 <script src="dist/cpexcel.js"></script>
@@ -179,6 +187,15 @@ function to_formulae(workbook) {
 	return result.join("\n");
 }
 
+function to_html(workbook) {
+	document.getElementById('htmlout').innerHTML = "";
+	var result = [];
+	workbook.SheetNames.forEach(function(sheetName) {
+		var htmlstr = X.write(workbook, {sheet:sheetName, type:'binary', bookType:'html'});
+		document.getElementById('htmlout').innerHTML += htmlstr;
+	});
+}
+
 var tarea = document.getElementById('b64data');
 function b64it() {
 	if(typeof console !== 'undefined') console.log("onload", new Date());
@@ -197,6 +214,7 @@ function process_wb(wb) {
 		case "form":
 			output = to_formulae(wb);
 			break;
+		case "html": return to_html(wb);
 		default:
 			output = to_csv(wb);
 	}
@@ -283,5 +301,16 @@ function handleFile(e) {
 
 if(xlf.addEventListener) xlf.addEventListener('change', handleFile, false);
 </script>
+<script type="text/javascript">
+	var _gaq = _gaq || [];
+	_gaq.push(['_setAccount', 'UA-36810333-1']);
+	_gaq.push(['_trackPageview']);
+
+	(function() {
+		var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;
+		ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';
+		var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);
+	})();
+</script>
 </body>
 </html>
diff --git a/test.js b/test.js
index 81162e5..af7afa1 100644
--- a/test.js
+++ b/test.js
@@ -714,7 +714,7 @@ describe('parse features', function() {
 				assert.equal(get_cell(ws, "B1").c[0].t, "Yegor Kozlov:\nfirst cell", "must have the concatenated texts");
 				if(i > 0) return;
 				assert.equal(get_cell(ws, "B1").c[0].r, '<r><rPr><b/><sz val="8"/><color indexed="81"/><rFont val="Tahoma"/></rPr><t>Yegor Kozlov:</t></r><r><rPr><sz val="8"/><color indexed="81"/><rFont val="Tahoma"/></rPr><t xml:space="preserve">\r\nfirst cell</t></r>', "must have the rich text representation");
-				assert.equal(get_cell(ws, "B1").c[0].h, '<span style="font-weight: bold;">Yegor Kozlov:</span><span style=""><br/>first cell</span>', "must have the html representation");
+				assert.equal(get_cell(ws, "B1").c[0].h, '<span style="font-size:8;"><b>Yegor Kozlov:</b></span><span style="font-size:8;"><br/>first cell</span>', "must have the html representation");
 			});
 		});
 		[
diff --git a/xlsx.flow.js b/xlsx.flow.js
index 6b24fd1..91b5e3a 100644
--- a/xlsx.flow.js
+++ b/xlsx.flow.js
@@ -5733,7 +5733,7 @@ var parse_rs = (function parse_rs_factory() {
 	var tregex = matchtag("t"), rpregex = matchtag("rPr"), rregex = /<(?:\w+:)?r>/g, rend = /<\/(?:\w+:)?r>/, nlregex = /\r\n/g;
 	/* 18.4.7 rPr CT_RPrElt */
 	var parse_rpr = function parse_rpr(rpr, intro, outro) {
-		var font = {}, cp = 65001;
+		var font = {}, cp = 65001, align = "";
 		var m = rpr.match(tagregex), i = 0;
 		if(m) for(;i!=m.length; ++i) {
 			var y = parsexmltag(m[i]);
@@ -5747,9 +5747,11 @@ var parse_rs = (function parse_rs_factory() {
 				/* 18.8.36 shadow CT_BooleanProperty */
 				/* ** not required . */
 				case '<shadow':
+					if(!y.val) break;
 					/* falls through */
 				case '<shadow>':
-				case '<shadow/>': break;
+				case '<shadow/>': font.shadow = 1; break;
+				case '</shadow>': break;
 
 				/* 18.4.1 charset CT_IntProperty TODO */
 				case '<charset':
@@ -5759,9 +5761,11 @@ var parse_rs = (function parse_rs_factory() {
 
 				/* 18.4.2 outline CT_BooleanProperty TODO */
 				case '<outline':
+					if(!y.val) break;
 					/* falls through */
 				case '<outline>':
-				case '<outline/>': break;
+				case '<outline/>': font.outline = 1; break;
+				case '</outline>': break;
 
 				/* 18.4.5 rFont CT_FontName */
 				case '<rFont': font.name = y.val; break;
@@ -5779,7 +5783,12 @@ var parse_rs = (function parse_rs_factory() {
 
 				/* 18.4.13 u CT_UnderlineProperty */
 				case '<u':
-					if(y.val == '0') break;
+					if(!y.val) break;
+					switch(y.val) {
+						case 'double': font.uval = "double"; break;
+						case 'singleAccounting': font.uval = "single-accounting"; break;
+						case 'doubleAccounting': font.uval = "double-accounting"; break;
+					}
 					/* falls through */
 				case '<u>':
 				case '<u/>': font.u = 1; break;
@@ -5810,7 +5819,7 @@ var parse_rs = (function parse_rs_factory() {
 				case '<family': font.family = y.val; break;
 
 				/* 18.4.14 vertAlign CT_VerticalAlignFontProperty TODO */
-				case '<vertAlign': break;
+				case '<vertAlign': align = y.val; break;
 
 				/* 18.8.35 scheme CT_FontScheme TODO */
 				case '<scheme': break;
@@ -5820,9 +5829,22 @@ var parse_rs = (function parse_rs_factory() {
 			}
 		}
 		var style = [];
-		if(font.b) style.push("font-weight: bold;");
-		if(font.i) style.push("font-style: italic;");
+
+		if(font.u) style.push("text-decoration: underline;");
+		if(font.uval) style.push("text-underline-style:" + font.uval + ";");
+		if(font.sz) style.push("font-size:" + font.sz + ";");
+		if(font.outline) style.push("text-effect: outline;");
+		if(font.shadow) style.push("text-shadow: auto;");
 		intro.push('<span style="' + style.join("") + '">');
+
+		if(font.b) { intro.push("<b>"); outro.push("</b>"); }
+		if(font.i) { intro.push("<i>"); outro.push("</i>"); }
+		if(font.strike) { intro.push("<s>"); outro.push("</s>"); }
+
+		if(align == "superscript") align = "sup";
+		else if(align == "subscript") align = "sub";
+		if(align != "") { intro.push("<" + align + ">"); outro.push("</" + align + ">"); }
+
 		outro.push("</span>");
 		return cp;
 	};
@@ -6776,6 +6798,7 @@ function parse_sty_bin(data, themes, opts) {
 	for(var y in SSF._table) styles.NumberFmt[y] = SSF._table[y];
 
 	styles.CellXf = [];
+	styles.Fonts = [];
 	var state = [];
 	var pass = false;
 	recordhopper(data, function hopper_sty(val, R_n, RT) {
@@ -6783,7 +6806,9 @@ function parse_sty_bin(data, themes, opts) {
 			case 0x002C: /* 'BrtFmt' */
 				styles.NumberFmt[val[0]] = val[1]; SSF.load(val[1], val[0]);
 				break;
-			case 0x002B: /* 'BrtFont' */ break;
+			case 0x002B: /* 'BrtFont' */
+				styles.Fonts.push(val);
+				break;
 			case 0x0401: /* 'BrtKnownFonts' */ break;
 			case 0x002D: /* 'BrtFill' */ break;
 			case 0x002E: /* 'BrtBorder' */ break;
@@ -16504,7 +16529,7 @@ function make_csv_row(sheet/*:Worksheet*/, r/*:Range*/, R/*:number*/, cols/*:Arr
 }
 
 function sheet_to_csv(sheet/*:Worksheet*/, opts/*:?Sheet2CSVOpts*/)/*:string*/ {
-	var out = "";
+	var out = [];
 	var o = opts == null ? {} : opts;
 	if(sheet == null || sheet["!ref"] == null) return "";
 	var r = safe_decode_range(sheet["!ref"]);
@@ -16518,10 +16543,10 @@ function sheet_to_csv(sheet/*:Worksheet*/, opts/*:?Sheet2CSVOpts*/)/*:string*/ {
 		row = make_csv_row(sheet, r, R, cols, fs, rs, FS, o);
 		if(row == null) { continue; }
 		if(o.strip) row = row.replace(endregex,"");
-		out += row + RS;
+		out.push(row + RS);
 	}
 	delete o.dense;
-	return out;
+	return out.join("");
 }
 
 function sheet_to_txt(sheet/*:Worksheet*/, opts/*:?Sheet2CSVOpts*/) {
diff --git a/xlsx.js b/xlsx.js
index a5ffee5..c38160c 100644
--- a/xlsx.js
+++ b/xlsx.js
@@ -5672,7 +5672,7 @@ var parse_rs = (function parse_rs_factory() {
 	var tregex = matchtag("t"), rpregex = matchtag("rPr"), rregex = /<(?:\w+:)?r>/g, rend = /<\/(?:\w+:)?r>/, nlregex = /\r\n/g;
 	/* 18.4.7 rPr CT_RPrElt */
 	var parse_rpr = function parse_rpr(rpr, intro, outro) {
-		var font = {}, cp = 65001;
+		var font = {}, cp = 65001, align = "";
 		var m = rpr.match(tagregex), i = 0;
 		if(m) for(;i!=m.length; ++i) {
 			var y = parsexmltag(m[i]);
@@ -5686,9 +5686,11 @@ var parse_rs = (function parse_rs_factory() {
 				/* 18.8.36 shadow CT_BooleanProperty */
 				/* ** not required . */
 				case '<shadow':
+					if(!y.val) break;
 					/* falls through */
 				case '<shadow>':
-				case '<shadow/>': break;
+				case '<shadow/>': font.shadow = 1; break;
+				case '</shadow>': break;
 
 				/* 18.4.1 charset CT_IntProperty TODO */
 				case '<charset':
@@ -5698,9 +5700,11 @@ var parse_rs = (function parse_rs_factory() {
 
 				/* 18.4.2 outline CT_BooleanProperty TODO */
 				case '<outline':
+					if(!y.val) break;
 					/* falls through */
 				case '<outline>':
-				case '<outline/>': break;
+				case '<outline/>': font.outline = 1; break;
+				case '</outline>': break;
 
 				/* 18.4.5 rFont CT_FontName */
 				case '<rFont': font.name = y.val; break;
@@ -5718,7 +5722,12 @@ var parse_rs = (function parse_rs_factory() {
 
 				/* 18.4.13 u CT_UnderlineProperty */
 				case '<u':
-					if(y.val == '0') break;
+					if(!y.val) break;
+					switch(y.val) {
+						case 'double': font.uval = "double"; break;
+						case 'singleAccounting': font.uval = "single-accounting"; break;
+						case 'doubleAccounting': font.uval = "double-accounting"; break;
+					}
 					/* falls through */
 				case '<u>':
 				case '<u/>': font.u = 1; break;
@@ -5749,7 +5758,7 @@ var parse_rs = (function parse_rs_factory() {
 				case '<family': font.family = y.val; break;
 
 				/* 18.4.14 vertAlign CT_VerticalAlignFontProperty TODO */
-				case '<vertAlign': break;
+				case '<vertAlign': align = y.val; break;
 
 				/* 18.8.35 scheme CT_FontScheme TODO */
 				case '<scheme': break;
@@ -5759,9 +5768,22 @@ var parse_rs = (function parse_rs_factory() {
 			}
 		}
 		var style = [];
-		if(font.b) style.push("font-weight: bold;");
-		if(font.i) style.push("font-style: italic;");
+
+		if(font.u) style.push("text-decoration: underline;");
+		if(font.uval) style.push("text-underline-style:" + font.uval + ";");
+		if(font.sz) style.push("font-size:" + font.sz + ";");
+		if(font.outline) style.push("text-effect: outline;");
+		if(font.shadow) style.push("text-shadow: auto;");
 		intro.push('<span style="' + style.join("") + '">');
+
+		if(font.b) { intro.push("<b>"); outro.push("</b>"); }
+		if(font.i) { intro.push("<i>"); outro.push("</i>"); }
+		if(font.strike) { intro.push("<s>"); outro.push("</s>"); }
+
+		if(align == "superscript") align = "sup";
+		else if(align == "subscript") align = "sub";
+		if(align != "") { intro.push("<" + align + ">"); outro.push("</" + align + ">"); }
+
 		outro.push("</span>");
 		return cp;
 	};
@@ -6715,6 +6737,7 @@ function parse_sty_bin(data, themes, opts) {
 	for(var y in SSF._table) styles.NumberFmt[y] = SSF._table[y];
 
 	styles.CellXf = [];
+	styles.Fonts = [];
 	var state = [];
 	var pass = false;
 	recordhopper(data, function hopper_sty(val, R_n, RT) {
@@ -6722,7 +6745,9 @@ function parse_sty_bin(data, themes, opts) {
 			case 0x002C: /* 'BrtFmt' */
 				styles.NumberFmt[val[0]] = val[1]; SSF.load(val[1], val[0]);
 				break;
-			case 0x002B: /* 'BrtFont' */ break;
+			case 0x002B: /* 'BrtFont' */
+				styles.Fonts.push(val);
+				break;
 			case 0x0401: /* 'BrtKnownFonts' */ break;
 			case 0x002D: /* 'BrtFill' */ break;
 			case 0x002E: /* 'BrtBorder' */ break;
@@ -16434,7 +16459,7 @@ function make_csv_row(sheet, r, R, cols, fs, rs, FS, o) {
 }
 
 function sheet_to_csv(sheet, opts) {
-	var out = "";
+	var out = [];
 	var o = opts == null ? {} : opts;
 	if(sheet == null || sheet["!ref"] == null) return "";
 	var r = safe_decode_range(sheet["!ref"]);
@@ -16448,10 +16473,10 @@ function sheet_to_csv(sheet, opts) {
 		row = make_csv_row(sheet, r, R, cols, fs, rs, FS, o);
 		if(row == null) { continue; }
 		if(o.strip) row = row.replace(endregex,"");
-		out += row + RS;
+		out.push(row + RS);
 	}
 	delete o.dense;
-	return out;
+	return out.join("");
 }
 
 function sheet_to_txt(sheet, opts) {